kqlMITfrom Azure/Azure-Sentinel
User account created and deleted within 10 mins

'Identifies when a user account is created and then deleted within 10 minutes. This can be an indication of compromise and an adversary attempting to hide in the noise.'
Quality
100
FP risk
—
Forks
Views
ATT&CK techniques
T1098 T1078
Rule sourceDetections/SecurityEvent/UserAccountCreatedDeleted_10m.yaml
let timeframe = 1d;
let spanoftime = 10m;
let threshold = 0;
(union isfuzzy=true
    (SecurityEvent
    | where TimeGenerated > ago(timeframe+spanoftime)
    // A user account was created
    | where EventID == 4720
    | where AccountType =~ "User"
    | project creationTime = TimeGenerated, CreateEventID = EventID, CreateActivity = Activity, Computer = toupper(Computer), 
    TargetAccount = tolower(TargetAccount), TargetUserName, TargetDomainName, TargetSid, 
    AccountUsedToCreate = SubjectAccount, CreatedBySubjectUserName = SubjectUserName, CreatedBySubjectDomainName = SubjectDomainName, SIDofAccountUsedToCreate = SubjectUserSid, UserPrincipalName
    ),
    (
    WindowsEvent
    | where TimeGenerated > ago(timeframe+spanoftime)
    // A user account was created
    | where EventID == 4720
    | extend SubjectUserSid = tostring(EventData.SubjectUserSid)
    | extend AccountType=case(EventData.SubjectUserName endswith "$" or SubjectUserSid in ("S-1-5-18", "S-1-5-19", "S-1-5-20"), "Machine", isempty(SubjectUserSid), "", "User")
    | where AccountType =~ "User"
    | extend SubjectAccount = strcat(tostring(EventData.SubjectDomainName),"\\", tostring(EventData.SubjectUserName))
    | extend SubjectDomainName = tostring(EventData.SubjectDomainName), SubjectUserName = tostring(EventData.SubjectUserName)
    | extend TargetAccount = strcat(EventData.TargetDomainName,"\\", EventData.TargetUserName)
    | extend TargetSid = tostring(EventData.TargetSid)
    | extend UserPrincipalName = tostring(EventData.UserPrincipalName)
    | extend Activity = "4720 - A user account was created."
    | extend TargetUserName = tostring(EventData.TargetUserName), TargetDomainName = tostring(EventData.TargetDomainName) 
    | project creationTime = TimeGenerated, CreateEventID = EventID, CreateActivity = Activity, Computer = toupper(Computer), 
    TargetAccount = tolower(TargetAccount), TargetUserName, TargetDomainName, TargetSid, 
    AccountUsedToCreate = SubjectAccount, CreatedBySubjectUserName = SubjectUserName, CreatedBySubjectDomainName = SubjectDomainName, SIDofAccountUsedToCreate = SubjectUserSid, UserPrincipalName
    )
  )
| join kind = inner 
(
  (union isfuzzy=true
    (SecurityEvent
    | where TimeGenerated > ago(timeframe)
    // A user account was deleted
    | where EventID == 4726
    | where AccountType == "User"
    | project deletionTime = TimeGenerated, DeleteEventID = EventID, DeleteActivity = Activity, Computer = toupper(Computer), 
    TargetAccount = tolower(TargetAccount), TargetUserName, TargetDomainName, TargetSid, 
    AccountUsedToDelete = SubjectAccount, DeletedBySubjectUserName = SubjectUserName, DeletedBySubjectDomainName = SubjectDomainName, SIDofAccountUsedToDelete = SubjectUserSid, UserPrincipalName
    ),
    (WindowsEvent
    | where TimeGenerated > ago(timeframe)
    // A user account was deleted
    | where EventID == 4726
    | extend SubjectUserSid = tostring(EventData.SubjectUserSid)
    | extend SubjectAccount = strcat(tostring(EventData.SubjectDomainName),"\\", tostring(EventData.SubjectUserName))
    | extend AccountType=case(SubjectAccount endswith "$" or SubjectUserSid in ("S-1-5-18", "S-1-5-19", "S-1-5-20"), "Machine", isempty(SubjectUserSid), "", "User")
    | where AccountType == "User"
    | extend SubjectDomainName = tostring(EventData.SubjectDomainName), SubjectUserName = tostring(EventData.SubjectUserName)
    | extend TargetSid = tostring(EventData.TargetSid)
    | extend UserPrincipalName = tostring(EventData.UserPrincipalName)
    | extend Activity = "4726 - A user account was deleted."
    | extend TargetUserName = tostring(EventData.TargetUserName), TargetDomainName = tostring(EventData.TargetDomainName) 
    | extend TargetAccount = strcat(EventData.TargetDomainName,"\\", EventData.TargetUserName)
    | project deletionTime = TimeGenerated, DeleteEventID = EventID, DeleteActivity = Activity, Computer = toupper(Computer), 
    TargetAccount = tolower(TargetAccount), TargetUserName, TargetDomainName, TargetSid, 
    AccountUsedToDelete = SubjectAccount, DeletedBySubjectUserName = SubjectUserName, DeletedBySubjectDomainName = SubjectDomainName, SIDofAccountUsedToDelete = SubjectUserSid, UserPrincipalName
    )
  )
) on Computer, TargetAccount
| where deletionTime - creationTime < spanoftime
| extend TimeDelta = deletionTime - creationTime
| where tolong(TimeDelta) >= threshold
| project TimeDelta, creationTime, CreateEventID, CreateActivity, Computer, TargetAccount, TargetSid, UserPrincipalName, AccountUsedToCreate, SIDofAccountUsedToCreate,
deletionTime, DeleteEventID, DeleteActivity, AccountUsedToDelete, SIDofAccountUsedToDelete, TargetUserName, TargetDomainName, 
CreatedBySubjectUserName, CreatedBySubjectDomainName, DeletedBySubjectUserName, DeletedBySubjectDomainName
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| project-away DomainIndex